Valve for rock drills



July 19, 1927. I I 36,632

C. C. HANSEN VALVE FOR ROCK DRILLS Filed Now--18, 1926 2 Sheets-Sheet 1U INVENTOR. 0/102 aaflzmaen 'Jul y 19,1927.

1,636,632 c. c. HANSEN VALVE FOR ROCK DRILLS Filed Nov.1 8, 1926 2Sheets-Sheet 2 INVENTOR. [b (trim [I Hansen- Patented July 19, 1927.

UNITED "STATES PATENT OFFICE.

CHARLES C. HANSEN, OF EASTON, PENNSYLVANIA, ASSIGNOR TO INGERSOLL-R ANDCOMPANY, OF JERSEY CITY, NEW JERSEY, ACORPORLATION-OF NEW JERSEY.

VALVE FOR ROCK DRILLS.

Application filed November 18,1926. Serial Ila 149,137.

This invention relates to rock drills, but more particularly to adistributing valve for fluid actuated rock drills of the hammer t e.

5 ilhe objects of the invention are to obtain a quick and positivevalveaction and to insure a heavy blow of the hammer piston against theworking implement.

Other objects will appear hereinafter.

In the drawings forming part of this specification,

Figure 1 is 'a sectional elevation of a rock drill showing the valveinposition to admit pressure fluid to the rearward end of the cylinder,

Figure 2 is a similar View showing the valve in position to admitpressure fluid to the front end of the cylinder, and r Figure 3 is aview similar to Figures 1 and 0 2 showing a modification of theinvention.

Referring to the drawings and at first more particularlyto Figures land2, A represents a cylinder having a free exhaust port B. A reciprocatoryhammer piston C is disposed in the cylinder A and in this instance has aplain reduced forward extension D to deliver blows of impact to aworking implement (not shown). The extension D'cooperates slidably witha head E which forms a I.)- closure for the front end of the cylinder,the rearward end of the cylinder A being sealed by a head F.

Disposed on the cylinder A is a valve chest G having a bore designatedgenerally byH. The outer portions J of the'bore H may be of uniformdiameter and in the present instance are sealed by hollow plugs K and Lthrough which extends a bolt 0 whereby the said plugs K and L areclamped securely in assembled position.

Intermediate the inner endsof the plugs,

K and L is a valve chamber P having a reduced bore Q, at its rearwardend. The rearward end of the bore Qis inthis instance in constantcommunication with the atmosphere through an exhaust passage R.

Pressure fluid for operating the drill may be introduced into the valvechamber P through a suitable connection 'S communicatp between thecentral forwardly of the central port T and 'atits other end with thefront end of the. cylinder A. A slmilar inlet passage "W in the rearwardendof the cylinder A affords communication between the forward end ofthe cylinder and the valvechamber P rearwardlyof the central port T. Inthe present instance, a small passage X is formed in the .valve chest Gto establish communication port U andtherearward inlet passage W. I

The distribution of the pressure'fluid entering the central port T iseffected by a distributing valve Y preferably ofthe sleeve type. Thevalve Y in this instance has an enlarged bore Z to cooperate slidablywith an enlarged portion Z) of the bolt 0 and also has asmaller bore- 0to cooperate slidably with a reduced portioncl, of the bolt 0. Inthisway is formed a pressure chamber 6 in the valveY. An end wall 6 inthe chamber 6 serves as an actuatmg and holding -face" against whichpressure fluid may act to assist in throwing the valve rearwardly and tohold it in said rearward position. The pressure chamber 6 is in constantcommunication with the. centralport T through radial pasvalve which inthis instance has an outer actuating face 9 and controls the centralport T.

' An end head it of the same diameter as the central head 9 is formed onthe front end of the valve and inthis instance has a forward actuatingface j intermittently exposed to pressure fluid admitted from thecylinder A through a kicker passage lcto a pressure" chamber 0 in'thefront end of the valve chamber P for throwing the valve Y rearwardly. Anexhaust port 1) is formed in the valve chest G near the'forward end ofthe chamber P to permit the escape ofv pressure fluid admitted into theexpansion chamber -0 and also to permit the exhaust of air compressed bythe piston C in the front end of the. cylinder. This exhaustport p iscontrolled by the end headh.

'lOO

' cylinder to impel the piston forwardly. I111? i will be thrownrearwardly before all the air compressed by the piston will beexmediately prior to the uncovering of the free exhaustport B by thepiston C, the

kicker passage is will be uncovered and'a portion of the pressure fluidin the rearward end of the cylinder will flow through the said kickerport 70 into the expansion chamber and, assisted by the pressure fluidin the pressure chamber 6, will throw the valve to its'rearwardmostlimiting position. However, the valve Y is not thrown rearwardly untilthe piston C is about to deliver its blow against the working implementso that the air compressed by the piston G in the front end of thecylinder may be freely expelled through the front inlet passage V andthrough the valve chamber 1? between the heads 9 and ]L and through theexhaust port 770 The valve, however,

hausted to the atmosphere, thus entrapping a small portion of compressedair in the front end of the cylinder to slightly cushion the blow of thehammer piston C.

About the time that the valve Y reaches its rearwardmost limitingposition the expansion chamber 0 will be placed in communication' withthe exhaust passage thus permitting the escape of the pressure fluidutilized for actuating the valve rearwardly to the atmosphere. It willbe observed that the pressure fluid is not exhausted from the expansionchamber 0 until the valve has practically traveled the entire distancerearwardly. In this way is obtained a positive and quick valve actionand the tendency of the valve to flutter will be entirely elimi nated. 7

While the valve is in its rearward posi tion the pressure fluid existingin the pressure chamber 0 acting against the actuating face a will holdthe valve rearwardly thus v permitting a free flow of pressure fluidfrom the central port T through the valve cham ber P and through thefront inlet passage V into the front end of the cylinder to impel thepiston C rearwardly. After the piston C overruns the exhaust port 13'the air in the rearward end of the cylinder A will be compressed by thepiston and, being augmented by pressure fluid flowing through the smallport X, will act against the actuating face g of the central head 9 andwill again throw the vvalve forwardly to admit pressure fluid to therearward end of the cylinder, thus completing the cycle of operations.

In the modified construction shown in Figure 3 a valve 9 is disposed inthe valve chamber P and has a reduced forward extension r slidable in anexpansion chamber 8 in the forward sealing plug K. A passage t leadingfrom the central-port 'I, to

the front end of the expansion chamber 8 conveys pressure fluid theretoto act against a holding face u on the .end of the reduced extension rfor holding the valve rearwardly after it has been thrown by'thepressure fluid entering the expansion chamber 0 through the kickerpassage/c. The operation of this modified form of valve is similar inall respects to that of the preferred bination of a cylinder having afree exhaust port, a hammer piston in the cylinder, a valve chest havinga chamber with a reduced bore at one end, inlet passages leading fromthe chamber to the cylinder, a distributing valve in the chamber havinga central head and an end head ofthesame diameter, an actuating face'ononeend of the valve intermittently exposed 'to live pressure fluidfor throwing the valve in'onedirection, the opposite end of the valvebeing constantly exposed to atmospheric pressure, a holding face ofsmaller area thanthe actuating face constantly exposed to live pressurefluid for holding the valve in thrown position, an opposed actuatingand'holding face on the central head intermittently ex posed to aircompressed by the piston for throwing the valve andintermittentlyexposed to live pressure fluid flowing to'one end of thecylinder for holding the valve.

2. In a fluid actuated rock drill,the combination of a cylinder having afree exhaust port, a hammer piston in the cylinder controlling theexhaust port, a valve chest having a valve chamber with a reduced boreat one end, inlet passages leading from the valve chamber to thecylinder, a distributing valve in the chamber having a central head lit)pressure chamber in the valve having an actuating face constantlyexposed to live pressure fluid forholding the valve in such thrownposition, an actuating and holding face on the central headintermittently eX- head for exhausting live pressure fluid from posed toair compressed by the piston for the end of the valve chamber and forexthrowing the valve to another position and hausting air compressed by,the piston in the 10 intermittently exposed to live pressure fluid frontend of the cylinder. a

flowing to the rearward end of the cylinder In testimony whereof I havesigned this for holding the valve in thrown posit-ion, specification.and an exhaust port controlled by the end CHARLES C. HANSEN.

